ABSTRACT
We have developed two techniques for establishing the validity of those arguments the validity of which depends on the role of truth-functional sentence-forming operators. This involved giving a symbolic representation of arguments in English. We can establish the validity of the symbolized argument using circumstance surveyors or by manipulating the premises in accord with the rules of natural deduction to obtain the conclusion. As noted, this symbolic approach is fruitful just because validity is a matter of form and not content. We developed our symbolic language and our system of rules by abstracting from the English language and from natural reasoning. This creation developed to study arguments expressed in English can itself in turn become an object of study. In this chapter we investigate the system itself one result of which will be to show that the two approaches match up in the appropriate way. To begin this meta-study we need a precise characterization of what it is that we are investigating.
